Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
pōcillum, i, n. dim. [poculum], a little cup: pocillum fictile, Cato, R. R. 156: mulsi, Liv. 10, 42 fin.; cf. Plin. 14, 13, 14, § 91: argenteum, Suet. Vesp. 2.